What years will a 73-74 GS rear fit in?

Any earlier year GS's?

 

Unless Canadian a 71-72 Buick A Body is also a GM Corporate 8.5.

 

thanks Jim but I am still not perfectly clear. So will a 73or 74 GS go drummtondrummrear fit in a 71 or 72 gs with no mods?

Thanks buddy

 

Like Larry I think they are a different width.

 

The 73-77 A-body housings are completely different than the 64-72 A-body. It would be too much of a hassle to modify it to get it to work.However,the guts(gears & posi),will fit the 71-72 8.5" housings.
The 73-77 A-body housing IS the same as the 78-96 B-body(full size). Some of the B-body models have a different bolt pattern for the wheels,but all of the mounting points are the same.

 

Thanks for all the great info Gentlemen